The present disclosure relates generally to turbine engine assemblies and, more specifically, turbine engine assemblies including cooling systems.
At least some known gas turbine engines include a low pressure compressor, a core engine, and a low pressure turbine. The core engine includes at least one high pressure compressor, a combustor, and a high pressure turbine coupled together in a serial flow relationship. More specifically, the high pressure compressor and high pressure turbine are coupled through a shaft to form a high pressure rotor assembly. Air entering the core engine is mixed with fuel and ignited to form a high energy gas stream. The high energy gas stream flows through the high pressure turbine to rotatably drive the high pressure turbine such that the shaft rotatably drives the high pressure compressor. After discharge from the high pressure turbine, the gas stream continues to expand as it flows through a low pressure turbine positioned aft of the high pressure turbine. The low pressure turbine includes a rotor assembly coupled to a drive shaft and the low pressure compressor. The low pressure turbine rotatably drives the low pressure compressor through the drive shaft.
Many modern turbine engines operate at increasingly high temperatures to facilitate increasing engine performance and efficiency. However, operating at the increasingly high temperatures results in damage to hot gas path components over extended periods of operation. As such, at least some known turbine engines include active cooling systems that reduce temperatures of the hot gas path components. For example, the hot gas path components are sometimes cooled with a flow of compressor bleed air discharged from the high pressure compressor. However, the ability of the compressor bleed air to cool components of the turbine engine depends on the pressure and temperature of the compressor bleed air. Some hot gas path components require cooling air that has a different pressure and/or temperature than the compressor bleed air. Additionally, some high pressure compressors require cooling with cooling air that has a different pressure and/or temperature than the compressor bleed air. Accordingly, some turbine engines utilize external sources of cooling air to provide air having the required pressure and temperature. However, the external sources of cooling air increase the cost of assembling and operating the turbine engines. Moreover, it is impractical to cool some turbine engines, such as turbine engines used in aircraft, with external sources of cooling air.